Laser surface modification of UNS S31603 stainless steel using NiCrSiB alloy for enhancing cavitation erosion resistance

摘要: Abstract Laser surface modification using NiCrSiB alloy (Ni −16.5Cr −15.5Fe −3.5Si −3.8B −0.1C) on austenitic stainless steel UNS S31603 (Fe −17.6Cr −11.2Ni −2.5Mo −1.4Mn −1.4Cu −0.4Si −0.03C) was achieved by a 2 kW continuous wave Nd-YAG laser. The cavitation erosion and pitting corrosion characteristics of the laser modified in 3.5% NaCl solution at 23 °C were studied means 20 kHz ultrasonic vibrator peak-to-peak amplitude 30 μm potentiostat, respectively. layer flame sprayed steel. then scanned with beam. melt depth dilution substrate material increased decrease scanning speed. At low ratio thickness to depth, less secondary phases such as CrB, CrB 2 , Fe B M 7 (CB) 3 hardness observed laser-modified layer. resistance R e (reciprocal mean penetration) specimen 0.65 improved 2.7 times compared that as-received specimen. In addition, potential close protection shifted noble direction substantial amount (from −3 121 mV). 0.88 four very super duplex S32760 −25.6Cr −7.2Ni −4Mo −0.6Mn −0.7Cu −0.8W −0.3Si −0.2N −0.03C). However, its lowered from 359 50 mV active −238 mV. On other hand, degree damage judged morphology severe specimens. found be linearly related hardness. deformation mechanism specimens also investigated.